1. Field of the Invention
The present invention is related to a multi-band antenna and an electronic system, in particular to a printed monopole multi-band antenna with signal feeding using coupling effect, and a related electronic system.
2. Description of Related Art
The capability of computation and signal processing electronic devices is getting more powerful with advances in modern technology, especially the innovation in wideband network and multimedia services to meet the requirements of higher transmission rates.
The gradually progressive mobile communication network such as the LTE (Long Term Evolution) particularly defines the specification supporting multiple-frequency bandwidth in accordance with the fourth generation mobile communication protocol. That means the 4G/LTE mobile communication protocol is specified to cover bandwidths such as low frequency around 698 MHz to 798 MHz, high frequency around 2300 MHz to 2690 MHz, and further include more band ranges in the future. The advancement may result in higher mobile communication bandwidth and more various multimedia services. Compared to the current prevailing mobile systems such as 2G/GSM and 3G/UMTS, the 4G/LTE network system integrates the bandwidths in the 2G/3G/4G mobile systems. In addition to including the current technologies, the larger bandwidth and higher transmission offered by the 4G/LTE network system is attractive to the subscribers.
It is noted that the LTE network system applies much more wave bands, however the different countries may adopt the different band ranges and make their LTE systems not compatible with each other. For example, the LTE system in North America uses the range over 700/800 MHz and 1700/1900 MHz; the LTE system in Europe over 800 MHz, 1800 MHz, and 2600 MHz; the LTE system in most of the Asian countries uses the bands over 1800 MHz and 2600 MHz; and the system in Australia is in 1800 MHz. Therefore, an antenna in a terminal device may be required to support multiple frequency bands so as to possibly roam in many countries.